Austrian Markus Schleinzer makes an impressive directorial debut with “Michael,” the disturbing story of the title character, a 35-year-old pedophile who keeps a 10-year-old boy, Wolfgang, prisoner in the basement of his suburban home.

Under the circumstances, the lad’s life could be a lot worse. His subterranean room is neat and clean, and it has a toilet and sink as well as a stockpile of food and crossword puzzles.

He gets to go upstairs for dinner, to watch TV and to celebrate Christmas. His captor, a nerdy insurance agent, even takes Wolfgang to the zoo. They look like an average father and son, and, despite opportunities, the boy makes no attempt to escape.

Before moving behind the camera, Schleinzer was a longtime casting agent. One of the filmmakers he worked with was Michael Haneke (“The Piano Teacher”), whose subversive style is on display in “Michael” (not to be confused with the 1996 John Travolta movie of the same name).

Schleinzer’s script leaves one big question unanswered: How did Wolfgang (David Rauchenberger) get into his predicament in the first place?

But that’s a minor fault for a well-acted, otherwise tightly scripted movie that builds suspense with a series of unexpected twists and turns. To his credit, Schleinzer avoids exploitation, choosing to present Michael (Michael Fuith) as pitiable rather than evil.